Single powder photographic developers



Un s States 2,979,406 7 SINGLE POWDER PHOTOGRAPHIC DEVELOPERS John B. Taylor and Jerry S. Krizka, Binghamton, N.Y., assignors to General Aniline & Film Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed Apr. 11, 1956,. Ser. No. 577,452

8 Claims. (Cl. 96-66) -ateito monohydrochloride, pyrogallol, an alkali such as soa diumcarbonate, borax, sodium metaborate or the like, a preservative such as an alkali metal sulfite and an anti-. foggant such as potassium bromide. Under ordinary conditions of mixing and storage, such dry developers undergo decomposition reactions which adversely affect the photographic activity of the developers.

The art has been cognizant of this phenomenon and, in an effort to avoid it, has provided for the presence in such developers of an acidic stabilizer such as phthalic acid, anhydrous oxalic acid, boric anhydride, metaboric acid, potassium metabisulfite and the like. While these various acid stabilizers serve to promote the keeping qualities of such developers, they do not lead to optimum results, as is evident by the fact that developers con taining the same generally discolor within a period of two to three months. r l g I It is known that alkali metal polyphospha-tes have utility in photographic developers as sequestering agents for the salts which cause hardness of water, When used for this purpose, the alkali metal phosphates are employed-in small amounts, i.e., usually less than one gram perliter. a l i We have now discovered that the stabilizing ability of the usual acidic. stabilizers for single powder photo-T graphic. developers .is. surprisingly promoted by using. with said stabilizers, a substantially higher quantityof; a wme a -po s ho h te tha is us d h n h polyphosphate is to operate as a sequestering agent. Dry' powder developers containing the usual acidic stabilizers with such higher quantities of alkali metal polyphosphates 9 2,979,406 Patented Apr. 11, 1961 \Any of the usual alkali metal polyphosphates may b employed such as sodium hexametaphosphate, potassium hexametaphosphate and the like. Best results, however, are achieved by-use of the sodium hexametaphosphate and the use of this compound is, accordingly, preferred. The photographic developing agent may be any of those previously mentioned and it. maybe used alone or in admixture with other developing agents. Typically, we may use a mixture of N-methyl-p-aminophenol and hydroquinone, metol and 1-phenyl-3-pyrazolidone (phenidone), phenidone and hydroquinone or phenidone, N-methyl-p-aminophenyl and hydroquinone.

The preservative is preferably sodium sulfite usually in the anhydrous condition and the anti-fogging agent is potassium bromide. The alkali may be any of those used in compounding photographic developers, such as sodium carbonate, sodium hydroxide, sodium tetraborate, sodium metaborate or the like.

In compounding the aforesaid developer mixtures, one may proceed by first mixing the alkali'fnetal polyphosphate with the acidic stabilizer or stabilizers, adding and admixing the alkali, then the developing agent and finally the. other ingredients. However, if it be preferred, all the ingredients may be admixed simultaneously.

It is to be emphasized that the alkali metal polyphos- V phates, per se, have no stabilizing efiect whatsoever on single powder photographic developers. In other words,

taining sodium hexametaphosphate even in the quantities I heretofore specified, in the absence of an acidic stabilizer, show no" improvement 'over similar sing-1e powder de velo-pers' free from" the acidic stabilizer. Single pow der developers containing the usual acidic stabilizers absent thesodium hexametaphosphate discolor in a period of a few months When, however, the acidic stabilizers and the alkali metal polyphosphate in the noted quantity are present together in a, single powder developer, the stability ofthe" developer is greatly magnified and no discoloration appears even after storing the developer constitute the purposes and objects of the present in- The developers whichlare contemplated herein contain as their essential components an'alkali metal Polyphos-' phatejan organic developing agent, an alkali, a preservative, an z mtifpggingagent andgan acid stabi1izer.-- Developers with these components whichwehav'e found to be abl ari .nit aasdrd t a iq e wm siderable periods of time may be. compoundedjin'the following proportions, it be-m understoodtha't 'the-resulting dry powder is to be used'to make aliterofHde-ff veloping splutionz u 7 Ethylene diamin' tetra acetic acid *017: I a a H ms Phthalicacide gmlg' p 0.5 An alkali-metalpolyphosphate; 311 s,, j q e ul me ab sv t V Organic develo ing agent .2; J." v 41015,, di m a nat z mem dr 30-0. Alkali :5 {610 C v Sodiumsulfite; anhydrous.. 40.0 Preservativep rnethyl praminophenoha 112.0. Anti-fogging agent Hy ll p Sodium. :hexametapliOsPhate U;

4 s ew e e 1 for more than 12 months. It is manifest, the factsbeing as'stated, that the results must be attributable to some peculiar coaction between the hexametaphosphateand ,the acidic stabilizer which serves to greatly intensify thestabilizing action of the acidic component- The following examples will serve to illustrate Four,

invention, the parts being by weight r a' ttb in solution.

Example 11 Grams Sodium hexametaphosphate 3.0 Ethylene diamine tetra acetic. acid 1.0 Oxalic acid (anhydrous) 0.3 Potassium metabisulfite 2.5 Borax, pentahydr 5.0 Sodium sulfite, anhydrous 100. N methyl-p-aminophenol 1.2 Hydroquinone 8.0 Potassium bromide 0.5

Example III Grams Sodium hexametaphosphate 4.0 Ethylene diamine tetra acetic acid 0.8 Phthalic acid- 1.0 Potassium metabisulfite 10.0 Sodium carbonate, monohydrate 80.0 Sodium sulfite, anhydrous 50.0 Phenidone .25 N methyl-p-aminophenol 1.0 Hydroquinone 7.5 Potassium bromide 1.5

Example IV Grams Sodium hexametaphosphate 6.0 Ethylene diamine tetra acetic acid 0.8 Metaboric acid 2.0 Potassium metabisulfite 3.0 Sodium carbonate, monohydrate 8.0 Sodium sulfite, anhydrous 100.0 Phenidone .15 Hydroquinone 4.5 Potassium Bromide 0.5

Example V Grams Sodium hexametaphosphate 2.0 Ethylene diamine tetra acetic acid 0.8 Boric anhydrideu, 0.75 Potassium metabisulfite 6.0 Sodium carbonate, monohydrate 20.0 Sodium sesqni-carbonate 8.0 Sodium sulfite, anhydrous 50.0 N methyl-p-aminophenol 3. Hydroquinone 7.0 Potassium bromide 1.2

The quantity of the developer represented by the above formulae is to be dissolved in water to make one liter of developing solution.

Modifications of the invention will occur to persons skilled in the art. We, therefore, do not intend to be limited in the patent granted except as necessitated by the appended claims.

We claim:

1. A single powder photographic developing composition containing an organic photographic developing lowing amounts of these ingredients per liter of solution:

3. The composition as defined in claim I wherein sufficient alkali metal hexametaphosphate is employed to produce about 1 to 8 grams thereof per liter of developer solution.

4. A single powder developing composition containing suflicient of the following ingredients to produce, upon dissolution, a developing solution having the following amounts of these ingredients per liter of solution:

Grams Sodium hexametaphosphate 2 Ethylene diamine tetra acetic acid .7 Phthalic acid .5 Potassium metabisulfite 6 Sodium carbonate, monohydrate 30 Sodium sulfite, anhydrous 40 N methyl-p-aminophenol 2 Hydroquinone. 5 Potassium bromide 1 5. A single powder developing composition containing suificient of the following ingredients to produce, upon dissolution, a developing solution having the following amounts of these ingredients per liter of solusuificient of the following ingredients to produce, upon dissolution, a developing solutionv having the following amounts of. these ingredients per liter of solution:.

agent, an alkalimetal sulfite, an alkali selected from the group consisting of sodium carbonate, sodium hydroxide, sodium tetraborate and sodium metaborate, anantifogging agent, a sufiicient amount of an acid stabilizer selected from the group consistingof phthalic. acid, an hydrous oxalic acid, boric anhydride, metaboric acid and potassium metabis'ulfite to produce 0.5 to 12 grams, per liter. inv solution and a sufiicient amount of alkali metal hexametaphosphate to produce at least 1 gram per liter 2. A single powder developing jcomposition containing suflicieut. of, the' following ingredients to .produce,

upon dissolution, a developing solution havingithe fol- Grams Sodiumi hexametaphosphate 4 Ethylene diamine tetra acetic acid .8 Phthalic i V v 1 7 Potassium metabisulfi V .10 Sodium carbonate, monohydrate 80'" Sodium sulfite, anhydrous. 50 Phenidone M V l .25 N a methyl-p-aminophenol-.. c .1 Hydroquinone I y I 7.5 Potassium bromide 1.5

A single powder developing composition containing, sufficieuhofthe following'ingredie'nt's to produce,

-upondissolution, a developing solution having the fol-= lowing amounts of these ingredients per liter of solution:

Grams Sodium hexametaphosphate 6 Ethylene diamine tetra acetic acid .8 Metaboric acid 2 Potassium metabisulfite 3 Sodium carbonate, monohydrate 8 Sodium sulfite, anhydrous 100 Phenidone 15 Hydroquinone 4.5 Potassium bromide .5

8. A single powder developing composition containing sufficient of the following ingredients to produce, upon dissolution, a developing solution having the following amounts of these ingredients per liter of solution:

Grams Sodium hexarnetaphosphate 2 Ethylene diamine tetra acetic acid .8 Boric anhydride .75 Potassium metabisulfite 6 Sodium carbonate, monohydrate 2O Grams Sodium sesqui-carbonate s 8 Sodium sulfite, anhydrous 50 N methyl-peminophenol 3.5

Hydroquinone 7 Potassium bromide 1.2

References Cited in the file of this patent UNITED STATES PATENTS 2,239,284 Draisbach Apr. 22, 1941 2,541,470 Henn et al. Feb. 13, 1951 2,610,122 John et a1. Sept. 9, 1952 2,688,549 James et a1 Sept. 7, 1954 FOREEGN PATENTS 7 520,753 Great Britain May 2, 1940 734,534 Germany Nov. 4, 1943 743,534 Germany Dec. 29, 1943 OTHER REFERENCES UNITED STATES PATENT OFFICE QERTIFECATE OF CORRECTION Patent NOE, 2,979,406 April ll, 1961 John B, Taylor's 2t a1;

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent. should read as corrected below.

Column 2 line 10, for 'metol" read l \Imethyl-paminophenol Signed and sealed this 10th day of October 1961 (SEAL) Attest: I

ERNEST W. sW'IDER 4 a DAVID L. LADD Attesting Officer Commissioner of Patents USCOMM-DC- 

1. A SINGLE POWDER PHOTOGRAPHIC DEVELOPING COMPOSITION CONTAINING AN ORGANIC PHOTOGRAPHIC DEVELOPING AGENT, AN ALKALI METAL SULFITE, AN ALKALI SELECTED FROM THE GROUP CONSISTING OF SODIUM CARBONATE, SODIUM HYDROXIDE, SODIUM TETRABORATE AND SODIUM METABORATE, AN ANTIFOGGING AGENT, A SUFFICIENT AMOUNT OF AN ACID STABILIZER SELECTED FROM THE GROUP CONSISTING OF PHTHALIC ACID, ANHYDROUS OXALIC ACID, BORIC ANHYDRIDE, METABORIC ACID AND POTASSIUM METABISULFITE TO PRODUCE 0.5 TO 12 GRAMS PER LITER IN SOLUTION AND A SUFFICIENT AMOUNT OF ALKALI METAL HEXAMETAPHOSPHATE TO PRODUCE AT LEAST 1 GRAM PER LITER IN SOLUTION. 